I'm fairly upset about the ending. If you'd not like to ruin your game like I did, read the spoiler below. However it will spoil the last mission for you.

[spoiler=Spoilers in Here] When you get the option to kill Michael, Trevor, or "Deathwish" choose deathwish. I assumed either way that all 3 protagonists would live (Who in their right mind lets a main character die??) So I killed Trevor. But apparently if you choose "Deathwish" everyone lives. [/spoiler]